The Geological Research And Target Evaluation Of Shahejie Formation,Tongkou-Yanling Area In Jizhong Depression

The research of sedimentary facies and sandbody is incomplete in the Tongkou-Yanling area.To solve the problem,through the analysis and research,based on seismic,drilling and logging data of the study area,and relevant theories like Petroleum Geology,Sequence Stratigraphy,Sedimentology,etc.,by using seismogeological integrative comprehensive research methods,this thesis does comprehensive studies on structural features,sedimentary systems,reservoir features,petroleum accumulation for identifying favorable reservoirs and target areas.First,on the basis of the fine stratigraphic correlation,the main target formations of the Tongkou-yanling area,Es1,Es2,and Es3 are divided into six reservoir groups and are further subdivided into 15 subzones.Tongkou-yanling area is located Lixian slope that is a monoclinic structure of towards the northeast and it is low-lying east and high west.The antithetic fault cut off north-west nose uplift and developed nose structure,the nose structure is favorable for hydrocarbon accumulation.The normal faults is the oil and gas horizontal and vertical migration of good channels.The sedimentary facies of Shahejie formation are mainly braided river delta facies in the withdrawal of water environment.In the part of this area is braided river facies.The main sub-phase delta plain and delta front,the most favorable micro-sedimentary facies type is sandbody of distributary channel and channel bar sedimentary.Because the dual control of the geological structure and the source of the sediments,most of Es1 is lithologic oil and gas reservoirs in the tectonic background;The oil bearing and connectivity of the channel sand is poor in Es2,so it develop into some small structural oil and gas reservoirs in the high position of nose structure only;The sandbody of Es3 is thick,continuous,oil and gas resources rich.And pinchout ofter appear in Es3,so the formation of lithologic trap is advantageous,it is main stratum for research.This thesis has clarified that the formation of the reservoir is the controlling effect of the structural evolution,the characteristics of fault development,sandbody distribution and sedimentary facies distribution,controlling occurrence,and it summarized the reservoir distribution and has Important significance to find new oil blocks and new oil-bearing series.